Section 8-502. Challenges; generally

Before his vote is cast at an election
  any  person  may  be challenged as to his right to vote, or his right to
  vote by absentee, military,  special  federal  or  special  presidential
  ballot. Such challenge may be made by an inspector or clerk, by any duly
  appointed  watcher,  or  by any registered voter properly in the polling
  place. An inspector shall challenge every person offering to vote,  whom
  he  shall  know  or suspect is not entitled to vote in the district, and
  every person whose name appears on the list of persons to be  challenged
  on election day which is furnished by the board of elections.